Thirty-seven blasts were monitored using either 3 or 4 seismographs at 4 coal strip mines and at a limestone quarry. Statistical analysis of the data shows that square root, cube root, and site specific scaling methods predict peak partical velocities with about the same degree of reliability. Some mines have peak particle velocities that are significantly lower or higher than the Bureau of Mines averages. This suggests that the option provided by the proposed regulations of the office of surface mining in 1983 to adjust blast designs based on site specific measurements could be highly beneficial both to operators and to the public. The frequency spectra reveal that the predominant frequencies were generally less than 50 hz, but several blasts had a significant amount of energy up to 125 hz. In some cases the vibration energy was concentrated at frequencies corresponding to the delay intervals.